Pulsejet engines are extraordinarily simple devices that provide an inexpensive means to provide thrust for an aircraft. Most pulsejets typically include a mechanical valve to prevent air and thrust from escaping through the inlet of the pulsejet when combustions occur in the combustion chamber of the pulsejet. A main disadvantage of these pulsejets is that they generally have a low efficiency and the mechanical valves have a limited durability. Some more recent pulsejet designs have implemented a pneumatic air inlet valve that eliminates the durability problem of the mechanical inlet valve. The pneumatic air valve generally injected air into a throat section of the inlet nozzle as the fuel in the combustion chamber ignited. This created a high pressure zone at the inlet nozzle throat that prevented thrust from the fuel combustion from escaping out the inlet. Notwithstanding the removal of the mechanical valve and greatly improved durability, implementation of the pneumatic air valve required supplemental equipment to provide and inject the air into the inlet nozzle of the pulsejet. And, the amount and complexity of the additional supplemental equipment significantly increases as the number of pulsejets included in a system multiply.
Additionally, a typical bank of pulsejets would include a plurality of round pulsejets aligned in columns and rows. In this configuration, the pulsejets where interconnected using a webbing of orthogonal walls that formed a grid of square compartments with a single pulsejet within each compartment. The interconnected webbing adds considerable weight to each pulsejet bank and the space created by round pulsejets in square compartments created gaps that could allow a portion of the thrust generated by each pulsejet to escape in the wrong direction.
A need therefore exists for a pulsejet engine design that reduces maintenance, weight and complexity of existing designs while increasing the thrust efficiency.